qm: s/Guest Boot Order/Device Boot Order/

[pve-docs.git] / pvecm.adoc

diff --git a/pvecm.adoc b/pvecm.adoc
index 390fb4b93ed5af347dc47cfd0dd9a8b498d9656b..cbbcf60fe8e0d55fcd29d98dbbd9f1a73475ec6c 100644 (file)
--- a/pvecm.adoc
+++ b/pvecm.adoc
@@ -61,7 +61,7 @@ Requirements
 
 * Date and time have to be synchronized.
 
-* SSH tunnel on TCP port 22 between nodes is used. 
+* SSH tunnel on TCP port 22 between nodes is used.
 
 * If you are interested in High Availability, you need to have at
   least three nodes for reliable quorum. All nodes should have the
@@ -327,11 +327,11 @@ After powering off the node hp4, we can safely remove it from the cluster.
 
 ----
  hp1# pvecm delnode hp4
+ Killing node 4
 ----
 
-If the operation succeeds no output is returned, just check the node
-list again with `pvecm nodes` or `pvecm status`. You should see
-something like:
+Use `pvecm nodes` or `pvecm status` to check the node list again. It should
+look something like:
 
 ----
 hp1# pvecm status
@@ -414,7 +414,7 @@ Delete the corosync configuration files:
 [source,bash]
 ----
 rm /etc/pve/corosync.conf
-rm /etc/corosync/*
+rm -r /etc/corosync/*
 ----
 
 You can now start the filesystem again as normal service:
@@ -869,6 +869,48 @@ pvecm status
 If you see a healthy cluster state, it means that your new link is being used.
 
 
+Role of SSH in {PVE} Clusters
+-----------------------------
+
+{PVE} utilizes SSH tunnels for various operations.
+
+* Proxying terminal sessions of node and containers between nodes
++
+When you connect another nodes shell through the web interface, for example, a
+non-interactive SSH tunnel is started in order to forward the necessary ports
+for the VNC connection.
+
+* VM and CT memory and local-storage migration, if the cluster wide migration
+  settings are not configured 'insecure' mode. During a VM migration an SSH
+  tunnel is established between the target and source nodes.
+
+* Storage replication
+
+.Pitfalls due to automatic execution of `.bashrc` and siblings
+[IMPORTANT]
+====
+In case you have a custom `.bashrc`, or similar files that get executed on
+login by the configured shell, `ssh` will automatically run it once the session
+is established successfully. This can cause some unexpected behavior, as those
+commands may be executed with root permissions on any above described
+operation. That can cause possible problematic side-effects!
+
+In order to avoid such complications, it's recommended to add a check in
+`/root/.bashrc` to make sure the session is interactive, and only then run
+`.bashrc` commands.
+
+You can add this snippet at the beginning of your `.bashrc` file:
+
+----
+# Early exit if not running interactively to avoid side-effects!
+case $- in
+    *i*) ;;
+      *) return;;
+esac
+----
+====
+
+
 Corosync External Vote Support
 ------------------------------
 
@@ -957,8 +999,17 @@ configured to do so.
 The traffic between the daemon and the cluster must be encrypted to ensure a
 safe and secure QDevice integration in {pve}.
 
-First, install the 'corosync-qnetd' package on your external server and
-the 'corosync-qdevice' package on all cluster nodes.
+First, install the 'corosync-qnetd' package on your external server
+
+----
+external# apt install corosync-qnetd
+----
+
+and the 'corosync-qdevice' package on all cluster nodes
+
+----
+pve# apt install corosync-qdevice
+----
 
 After that, ensure that all your nodes on the cluster are online.
 
@@ -969,8 +1020,10 @@ of the {pve} nodes:
 pve# pvecm qdevice setup <QDEVICE-IP>
 ----
 
-The SSH key from the cluster will be automatically copied to the QDevice. You
-might need to enter an SSH password during this step.
+The SSH key from the cluster will be automatically copied to the QDevice.
+
+NOTE: Make sure that the SSH configuration on your external server allows root
+login via password, if you are asked for a password during this step.
 
 After you enter the password and all the steps are successfully completed, you
 will see "Done". You can check the status now:
@@ -1256,9 +1309,9 @@ iface vmbr0 inet static
     address 192.X.Y.57
     netmask 255.255.250.0
     gateway 192.X.Y.1
-    bridge_ports eno1
-    bridge_stp off
-    bridge_fd 0
+    bridge-ports eno1
+    bridge-stp off
+    bridge-fd 0
 
 # cluster network
 auto eno2